Weather compensation & Wireless TRV control

[wads]

Intergas will work with Evohome and accept the OpenTherm bridge.

Ok, after much research I have decided to not got for EvoHome yet since it will cost £1500 to kit out the whole house. It's tough as I love a gadget and I'm really really into the smart system idea but I think prices must come down significantly in the next 18 months as competition increases and new versions are released.

Instead, I'm going to buy a future proofed boiler, install manual TRVs and use WC.

So I'm going for the Intergas HRE 30 SB with the WC sensor. I like the simplicity of the Intergas design and that it supports OpenTherm and WC.

I already have 2 HCW80 stats and a ST9400C timer from the old system so will reuse those.

We're going to get partial UFH downstairs in about 6 months so will future proof for that too.

I'll spend the difference on the cost of the full EvoHome on better insulation.

So my installation plan now looks like this:

1. Intergas HRE 30 SB with the WC sensor (in garage)
   
2. Unvented 300L cylinder (with boiler in garage)
   
3. 11 rads
4. 3 towel rails
5. Manual TRVs
6. 2 HCW80 stats and a ST9400C timer on 2 zones (upstairs, downstairs)
   
7. 2 zone UFH in half of ground floor in 6 months
8. Secondary hot water circuit to compensate for hot water lag (cylinder had to go in garage)
   
9. money saved (on not buying into evoHome yet) spent on insulation
10. buy into smart system in 18 months

Would anyone care to improve on that?

Is there a better programmable timer (bearing in mind that ebay is now flooded with decent second hand non-smart options but that the existing one will probably be replaced for a smart system)?

Thanks for all the input everyone. It's been educational.

 

[Dan Robinson]

Do you know how you'll control the weather compensated heating with a hot water cylinder?

 

[Biggles..]

Tupperware party here we come!

 

[wads]

Do you know how you'll control the weather compensated heating with a hot water cylinder?

I didn't but I know the theory now: http://www.atmos.co.uk/wp-content/u...Weather-compensation-and-stored-hot-water.pdf.

That's quite a n old doc. I'll find out if this is still applicable to the newer Intergas boilers. Imagine it is.

 

[D_Hailsham]

Do you know how you'll control the weather compensated heating with a hot water cylinder?

I didn't but I know the theory now

Neither diagram ensures that CH is turned off when you call for HW, which means that the boiler could be pumping water round the rads at 80C. The only way to overcome that is to set the timings so CH and HW are never on at the same time.

 

[vulcancontinental]

That is not the only way.

 

[wads]

Do you know how you'll control the weather compensated heating with a hot water cylinder?

I didn't but I know the theory now

Neither diagram ensures that CH is turned off when you call for HW, which means that the boiler could be pumping water round the rads at 80C. The only way to overcome that is to set the timings so CH and HW are never on at the same time.

... but assuming I'm happy to have the WC disabled while the HW is being heated I'm OK?

 

[Dan Robinson]

The only way to overcome that is to set the timings so CH and HW are never on at the same time.

Twaddle.

Can be done several ways, easiest being hot water priority.

Another is to use a mixing valve, but with Evohome that would get very expensive.


No Tupperware either Lee can all be done with what's in the evo boxes.

 

[Dan Robinson]

Do you know how you'll control the weather compensated heating with a hot water cylinder?

I didn't but I know the theory now: http://www.atmos.co.uk/wp-content/u...Weather-compensation-and-stored-hot-water.pdf.

That's quite a n old doc. I'll find out if this is still applicable to the newer Intergas boilers. Imagine it is.

They got that idea from me.

Yes it does work with the new boilers but there is a more elegant solution.

 

[Biggles..]

Now which wat round does that 3 port divertor go and which pin do you use.

 

[Dan Robinson]

Don't need that method either

 

[D_Hailsham]

The only way to overcome that is to set the timings so CH and HW are never on at the same time.

Twaddle.

Can be done several ways, easiest being hot water priority.

I should have made myself clearer. What I was trying to say was: if you followed the wiring diagrams shown, the only way of ensuring the rads did not have water at 80C running through them when HW is called is to have mutually exclusive timing for CH and HW.

Hot water priority is obviously better, but you still have to disable the external sensor.

 

[Biggles..]

Google won't help you with this one

The Intergas has some cunning little tricks hidden in its depths that aren't in the manuals.

The new rf version is even cleverer with what it can do with another companies controls.

None of which is published, i know some are playing with them so see what it can do before its all printed as being genuine manufacturers advice.

 

[MJGas]

You don't need to disable the external sensor

 

[MJGas]

This is the preferred method of installing an Intergas with Evohome.